What is cancer of the renal pelvis or ureter?
Cancer of the renal pelvis or ureter starts in the cells of the renal pelvis (a hollow part of each kidney) or ureter (a tube that connects each kidney to the bladder). A cancerous (malignant) tumour is a group of cancer cells that can grow into nearby tissue and destroy it. The tumour can also spread (metastasize) to other parts of the body.
Cells in the renal pelvis or ureter sometimes change and no longer grow or behave normally. In some cases, changes to these cells can cause cancer. Most often, cancer starts in urothelial cells that line the inside of the renal pelvis or ureter. This type of cancer is called urothelial carcinoma (also called transitional cell carcinoma). It makes up about 90% of all upper urinary tract tumours. Urothelial carcinoma starts in the renal pelvis more often than the ureter, but it can also be found in both places at the same time.
Rare types of renal pelvis and ureter cancer can also develop. These include squamous cell carcinoma and adenocarcinoma of the renal pelvis or ureter.
The renal pelvis and ureter
The renal pelvis and ureter are part of the urinary system and make up the upper urinary tract. The renal pelvis is a hollow part in the middle of each kidney. The ureters are thin tubes that connect the kidneys to the bladder. Each ureter is about 25 to 30 cm (10 to 12 inches) long.
Urine (pee) is your body’s liquid waste and is made by the kidneys. It collects in the renal pelvis then travels along the ureters to the bladder where it is stored. When the bladder is full of urine, it passes out of the body through the urethra.
Layers of the renal pelvis and ureter
The walls of each renal pelvis and ureter are made up of 3 main layers of tissue.
The urothelium is the inner lining of each renal pelvis and ureter. It continues as the lining for the bladder and urethra. It is made up of urothelial cells (also called transitional cells), which can stretch and change shape as urine flows. The urothelium is also called the transitional epithelium.
The lamina propria is a thin layer of connective tissue that surrounds the urothelium of each renal pelvis and ureter. It contains blood vessels, nerves and glands.
The muscularis propria is a thick, outer muscle layer of each renal pelvis and ureter. It is made up of muscle that works automatically without you thinking about it (called smooth muscle). It pushes urine from the kidney down to the bladder.
Other tissues that surround the kidneys and ureters are:
- adventitia – loose connective tissue that covers the kidneys and ureters
- fat – a layer of fat that surrounds the renal pelvis, kidney and ureter
One of a pair of bean-shaped organs at the back of the abdomen (on each side of the spine) that maintain the balance of water and minerals in the body, play a role in regulating blood pressure, produce certain hormones, filter waste from the blood and produce urine.
Urine made in the kidneys passes through the ureters to the bladder.
Renal means referring to or having to do with the kidneys, as in renal failure.
The muscular sac in the pelvis that receives urine from the ureters (tubes that carry urine from the kidneys), stores it and passes it from the body through the urethra.
The pathway that urine takes from the kidneys to the urethra.
The urinary tract includes the renal pelvis in the kidneys, as well as the ureters, bladder and urethra.
The group of organs that make, collect, store and pass urine out of the body.
The urinary system includes the kidneys, ureters, bladder and urethra.
A specialized organ or group of cells that produces or releases substances (such as hormones, saliva, digestive juices, sweat, tears or milk) to perform different functions in the body.